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Concentricity gauges, let's hear it if bench loaders and accuracy guys....

Discussion in 'Handloading and Reloading' started by RussellC, Sep 11, 2017.

  1. Walkalong

    Walkalong Moderator

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    I agree, fix the problem at the source.
     
  2. murf

    murf Member

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    i have found, measuring win and r-p cases in 270 win and 30-06 respectively, that a case, when loaded, that has excessive runout will always have exessive runout. it never gets better. a case with zero runout in one loading may have .002" runout in the next loading and go back to zero runout in the next loading. similarly, a case with .006" runout in one loading can have .004" runout in the next loading and .008" runout in the next loading.

    i have never seen a case go from .006" runout to .002" runout. if a case is crooked, it stays crooked.

    when i measure runout on my rcbs concentricity gauge, i mark the runout on the side of the case with a sharpie. since i don't tumble my cases, the runout number stays on the case for the next reloading and i can see that that case never gets worse, or better.

    fyi,

    murf
     
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  3. fotheringill

    fotheringill Member

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    I use the 21st Century gauge. It has the "flippy" needle so there is a lot less pressure on the case or bullet as with the regular "dial (needle) indicator. See picture in post #19 in this thread.
    I had the Hornady and sent it back. If you correct by pushing in one place, it is going to push in another, defeating the whole purpose IMO.
     
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  4. RussellC

    RussellC Member

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    I will have a look at this one,

    Thanks
    Russellc
     
  5. RussellC

    RussellC Member

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    Yes, I like that one. With the "Wheel" it is 239.00. Without the wheel, 179.00. The wheel alone is an additional 60.00. I must be missing something, it appears that if I buy them separate, its 229.00? I must be missing something.

    The more I look at this one, the more I like it! Thanks!

    Russellc
     
  6. 444

    444 Member

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    That is one of the ones I have been looking at also.

    That wheel IMO makes the whole thing. That is the thing I don't like about the Sinclair: holding the case down in the blocks and rotating the case.
     
  7. Walkalong

    Walkalong Moderator

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    The wheel makes it easier to rotate the case without human error moving the case. The 21st Century gauge is actually a good value IMHO. It's a much better design than the one I have, and I have often considered getting one. The Sinclair offering is also interesting.

    Once you figure out what dies need replacing, and what works, you can almost retire it.
     
  8. jmorris

    jmorris Member

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    179+60=239

    I ran a lever arm style indicator on mine for awhile but I use the 1" dial most often, the lever style cost more than a regular 1" dial indicator and because they are measuring angular displacement vs linear displacement and susceptible to cosign error if not positioned correctly.

    How much the wheel makes life easier depends on how you are using the gauge. If the contact points are very close to one another like this, it can be difficult to use without it. Not that you would use them that close on many rounds but they will be that close on a .17 Hornet case.

    image.jpeg

    If it's a long rifle case and you are off the shoulder it's not as big a help and I wouldn't spend $60 on just the wheel but then again I didn't buy a gauge in the first place.
    image.jpeg
     
    Last edited: Sep 14, 2017
  9. jmorris

    jmorris Member

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    You don't have to get super fancy to just get measurements than can show you if changes make things better or worse. Just something you can spin the case in and have an indicator mounted somehow will work. Other methods just make things easier. It's worth noting that these 3 methods are not measuring from the same points of contact, yet all 3 results, in this case are the same.



    And yeah I could have used a "good" round but there wouldn't have been much to see at that point.
     
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  10. GW Staar

    GW Staar Member

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    Agreed. The simple RCBS tool I use is ... well... adequate. But it works as often as I need it.....and it measures neck thickness as well.

    I like your video.....easily a thousand words.

    The following I just edited....realizing what I wrote first didn't make sense....o_O

    The last time I was down that "rabbit hole" mentioned above, I discovered something else interesting, concerning sizers with expander/distorters inside and LC brass.

    After polishing the hell out of the expander ball, I discovered that sizing typically .004" out LC 762 cases, might result in the case being minimally improved to .003" out.

    Yet turning the case a third and resizing, improved it more, resulting typically .002", then turning the case another third in the shell holder, and resizing a third time almost always brought it to .001! Yeah, nearly every time. This was MG brass!

    I believe someone mentioned, ".0005 a side" ? :)

    Though work hardening the brass in the neck two more times isn't exactly a sane positive use of time, I was curious.

    I was surprised that it does straighten crooked brass pretty darn well. And one can always anneal it, something worthwhile for that MG brass anyway, and have good, straight brass.........cheap.
     
    Last edited: Sep 14, 2017
  11. RussellC

    RussellC Member

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    OK, I am missing 10.00 in my math! Thanks for the info, looks like what I am looking for.

    Russellc
     
  12. Walkalong

    Walkalong Moderator

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    After I read it twice it did. :)
     
  13. jmorris

    jmorris Member

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    I was tracking, that last paragraph in post #8 was helpful for me in figuring out what I had and what I was doing to it and why, what was happening, was happening.

    It's not very easy to explain unless you want to write a paper on the subject but it's easy to see when you do one operation at a time excluding anyother operation and measure at every step along the way.

    For me at was more instrumental in getting uniformly great results and much more helpful than just being able to cull rounds that didn't turn out as well as I wanted.
     
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  14. RussellC

    RussellC Member

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    What I had in mind was making sure my reloading isnt the problem, and if so, is what I am doing about it correcting the problem I was causing? While perhaps off thread, this is my thread and I am sure most here would love to hear any tips for improving precision, DO TELL! please.

    Russellc
     
  15. jmorris

    jmorris Member

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    Change one thing at a time, observe the results of the change and if at all possible remove yourself as much as possible from interference with the results.
     
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  16. WelshShooter

    WelshShooter Member

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    I've never measured the runout of my handloaded ammunition so I cannot comment on how controlled my TIR is. I do, however, follow simple steps that bench rest shooters do.

    1. Use good quality components. What's the point in controlling TIR if you're using the cheapest bulk bullets? Good case brands, such as Lapua, will already have uniform case wall thicknesses without any further work required.
    2. Full length size your brass, don't neck size. I set my dies to bump the shoulders back 0.002", keeps the case neck concentric to the case body.
    3. Use the right amount of neck tension. If you size the case too much and force a bullet in during seating, you can affect the TIR.

    These steps should help produce concentric ammunition. At short range (e.g. 100 yards) the effects of concentric ammunition are not really noticeable, but I found my 6.5x47 Lapua rounds had better precision for longer distances (e.g. 1,200 yards). Heck, my ammunition may not have any difference in TIR at all, but more of my rounds were hitting the target compared with my previous batch where I neck sized my cases rather than full length/shoulder bump (that was the only difference, I always did steps 1 and 3 anyway). This difference in precision may very well have been due to slightly lower case capacity compared with neck sizing cases, or it may be down to more controlled concentricity and TIR as stated before. Irrespective, I size my cases that way now.
     
  17. Varminterror

    Varminterror Member

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    I would have kicked this to you in PM, but since you asked - I'll try to keep this brief within each bullet point, so I don't bury the thread, OP, or readers, but a few thoughts on reloading precision ammunition and precision shooting practice, but you know me well enough to know this won't be brief:

    • Consistency is king - and there are two types of controls to get it: Feed Forward and FeedBack, you need to learn to use both. Feed forward are the things you do, feedback are things you read/review. So a feed forward control is how you throw or weigh your charges - a Prometheus will throw more consistent charges than a Lee scoop, so that's a more consistent feed forward control for input consistency. However, you also need to read feed back from your charges to measure the output consistency, and using the powder throwing example, you need to be able to tell whether your charge weight is balanced a tight rope, or standing in the middle of a 4 lane highway. How far can you move on your powder charge before it really affects your ES on the back end? This is where you'll hear guys talk about accuracy nodes, charge windows or forgiveness, magic loads which shoot well in any rifle, Ladder Testing, or OCW = Optimal Charge Weight. A guy might find a VERY precise load at 44.4grn which gives the velocity they want, but if 44.2 and 44.6 are all over the map, it's the wrong powder for the application, pick a different powder. Similarly, if you find a very precise load at 100yrds, but it has an ES of 40fps, you gotta change powder or charge weight (feedback) because that's going to present itself as vertical when you get out at range. Powder choice and charge weight precision are feed forward controls, ES and OCW/Ladder testing are feed back measures.

    • Your precision is only as good as the worst of your ammo, your rifle, and your skill - so be sure you balance these 3 appropriately and be sure your ammo and your rifle are capable of better ammo than you are as the shooter. Crappy barrels won't shoot 1/3moa groups even with precision ammo, and perfect barrels won't do well with inconsistent ammo. If you're shooting factory chambers and factory barrels, there is a high likelihood your bore and chamber are not perfectly concentric, or the axis of each might not even be parallel (not concentric = coke cans laying on two different steps, non-parallel is one can on a flat, one on the side of a hill), or worst, they might be off for both concentricity AND parallelity (it's a word, but it sounds REALLY stupid when said out loud). A buggered crown will never shoot as well as a cleanly cut crown no matter what ammo it is fed. Making perfectly concentric ammunition with cheap FMJ's with inconsistent jacket thicknesses won't pay off either. This is why you often hear guys say neck turning in a factory chamber won't usually make a noticeable difference - because often, you're correcting a thou or two on the ammo, but might be 5 off center in the rifle. Loading powder charges down to the single kernel will not improve precision for a barrel with too slow of twist for the bullet. Very precise ammo can be made on Lee presses and Dies, so don't misconstrue what I'm saying, but be sure you aren't making perfect ammunition and feeding it into a "less than perfect" chamber and bore.

    • Decide your application first - this will determine the bullet you need to use (construction and BC) and what you need it to be able to do (velocity it needs to fly). Once you have your bullet decided, the velocity needed determines which cartridge case you put behind it, and what twist rate and barrel length you need to stick in front of it.

    • Once you do pick a bullet, it's a good idea to make a dummy round, then send that dummy to your barrel maker or gun builder to have them chamber and throat the barrel to match that bullet.

    • Monometals and partition type bullets (Nosler Partition, Swift A-frame) tend to like a bit of a run at the lands, start these around 50thou off, whereas any cup/core, poly tipped, HPBT, bonded, or match type bullet will typically do best with a short run. Secant ogive bullets may need to kiss or even be jammed. TTSX's have frustrated a lot of guys who try to load them like A-max's.

    • New resized brass or once fired and FL resized brass have proven to have the most potential for maximal precision, however, almost none of us actually live by that, largely because it costs too much, and of course, introducing new brass introduces a new variable. You'll hear a lot of guys say shoulder bumped ammo is more precise - I'm not sure I buy that, but shoulder bumping DOES increase brass life, so you can pick which means more to you, brass life or precision. But it's something to remind yourself - brass doesn't get better with age, it only gets worse. Most of us just deal with that and run our brass until the pockets go loose.

    • Bumping the shoulder with a FL die is FL sizing. Period. It's not neck sizing. Nothing wrong with that, but that's a reality. There are bump dies on the market which don't touch the case body, and there are neck sizing dies on the market which only touch the neck, if you REALLY want to only bump, or only neck size. I usually bump with a FL, meaning I FL size minimally, to help ensure my neck and body at the shoulder are concentric - and because I'm too cheap and too lazy to set up my bump dies most of the time.

    • Annealing is well worth the cost & trouble. It won't significantly improve your precision, but it WILL significantly improve your brass life. For 223, 1:3-1:4 loadings is usually sufficient, for 6.5-284, ever loading is best. For your 6.5 creedmoor, every other will keep your brass happy. Annealing will stop neck and shoulder splits, so your brass will die of loose pockets or wall splits - think of that as dying of old age instead of a car wreck. There are companies out there who will do contract annealing, and going in with a buddy on annealing machines does make a lot of sense, if you don't want to own one for yourself.

    • Incredibly precise factory ammunition can be bought, which is expensive, but saves a lot of investment in reloading gear and a lot of time reloading. I know a few guys who are placing regularly at PRS club matches with factory loads. Prime does very well. I've shot Hornady Match ammo to sub-moa and moa steel out to 1,000yrds. FGMM has earned its name. I've also known guys who have taken factory ammo as their "dummy round" for their barrel maker to match with the chambering/throating reamers - basically making a custom chamber to match their factory ammo.

    • Lapua brass is well worth the cost. It's hard to fork over the money for them, and you likely won't see a significant improvement in precision (it's there and it's real, just really hard to find for most shooters), but you'll see a significant improvement in brass life.

    • If you are measuring concentricity, then you're almost assuredly stuck with neck turning also. The case neck can make contact with the chamber neck, so if the neck wall isn't uniform, and resting on one side of the chamber, it will push the bullet off of the centerline of the bore. Also remember why we're measuring concentricity - we want the bullet to release into the rifling such it is coaxial to the bore. Tangent ogive bullets, and hybrids, will help self align better than Secant ogive bullets (VLD's), so as I mentioned above about powder choice - you can choose a bullet with more or less forgiveness for run out. I measure concentricity on the case neck, and two points on the ogive.

    • Weight sorting brass/bullets/primers, measuring/correcting concentricity, odd number land/groove barrels, poly or ratchet rifling, uniforming meplats & retipping bullets, neck turning, measuring powder to the nearest kernel, chasing the lands (actively moving the seating depth as your throat erodes), loading on a high precision arbor press, and a hundred other voodoo practices will make VERY little impact on your loads if you have chosen 1) well matched bullet weight/length, velocity, and twist rate, 2) a forgiving powder & charge weight, and 3) a forgiving tangent or hybrid ogive bullet (and a bullet jump which matches your bullet type). All of these voodoo items I've listed together will close the gap on those last few percent of possible precision, but the sum of ALL of these won't make as much difference as those 3 aspects. Picking a better suited powder and charge combination might take you from 1moa to 1/2moa, in general, barring really specific cases, tipping bullets or sorting based on concentricity or neck turning might take you from 0.6moa to 0.5moa - and it takes a lot of barrel life to shoot enough to prove that.

    • Barrels are consumable - get used to that. Chronological life is relative - a PRS Finale qualifier, who shoots a match every weekend and somewhere 4,000-10,000rnds per year will go through 2-4 barrels a year. A whitetail hunting rifle might get passed down for 200yrs before it burns out. A guy ringing steel once every month or two during "good weather months" might burn a barrel every 2-3yrs... But a guy doing much precision shooting should figure somewhere between a dime and a 50 cent piece per shot in barrel cost, and save for their new barrels according to their shooting volume rate.

    • If you're long range shooting, a combination of 2, 3, or even 4 rifles can be well worth while and make good financial sense. A 22LR, a 223rem/6.5grendel, a 243win/6.5creed/308win, and a 300RUM/338Edge/338Lap/50bmg would be a 4 rifle battery which will help a guy reach ELR without breaking the bank. If you only want to ring steel at 1,000, then a 22LR or 223 and a 6.5 creed/308win will be fine, or all 3 - 22LR, 223, 6.5. Don't underestimate the value of a 22LR - for 10c per round, a guy can use shorter ranges, get nearly infinite barrel life, have zero appreciable recoil, and have a lower cost rig overall (don't need as much scope to get to 400 as you do 1,400). It doesn't take many shots with a 300WM for the ammo cost of shooting a 22LR practice rifle to pay for the rifle.

    • Having good spotters with good spotting scopes and shooting on good ranges will save ammo and improve the shooters quality of practice. If a shooter gets feedback on every shot, they learn faster, get better DOPE, and can find the target faster. The field makes a difference as well. Shooting in a wheat field, cattle pasture, or rocky hills means you won't see bullet splashes, so unless your spotter can read trace well, you might as well be shooting in the dark. A crappy spotting scope will also mean you can't see strikes or splashes, let alone resolve mirage and trace, so that's not a place to skimp on gear.

    • You don't have to chase smaller and smaller groups to deliver hits on target at long range. At 100/200yrd benchrest games, your primer choice can make the difference between placing at a match and coming in at the middle of the pack. In longer range games, other factors are amplified so your actual rifle precision becomes less critical. Well worth the google and the time to read it: Bryan Litz and the AB crew put out a fantastic data set, which was summarized in equally fantastic fashion on Precision Rifle Blog in the last couple years ("How much does it matter precision rifle blog" in google and you'll get it). They did a monte carlo simulation to establish a sensitivity to different factors for what they call their "WEZ" or "Weapon Engagement Zone" (If memory serves). Their simulation combines different variables in a statistical distribution, so you can see how shrinking variability in different variables actually affects hit probability on target - accurate wind reading mattered the most, picking a cartridge with superior ballistics was second most valuable (less sensitivity to wind & less drop per yard, i.e. faster and better BC), and accurate range reading was 3rd. Bumping to max speed for the cartridge, tightening groups, and shrinking velocity spreads all tied for "almost doesn't matter at all," nearly a full order of magnitude behind the other 3 variables simulated, contributing 2-4% more hits on target each. Admittedly, I've been mad at myself of late because my eyes and skills have waned to the point I'm solidly a 0.6-0.8moa shooter, about twice the size on the same quality of equipment as a decade ago. That bugged me a LOT, until I looked at this systematic work from AB - which explicitly spelled out the value of shrinking 0.8 to 0.3moa - which only meant 4% more hits on target. We all like tiny groups at 100 and 200, but if you're shooting 1MOA or less, you're in the game. If you want to COMPETE at 1,000yrd benchrest or F-class, I was taught 1" at 300yrds is your standard to see if you can be in the hunt, but steel games are WAY less stringent than BR.
     
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  18. RussellC

    RussellC Member

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    @ Varminterror: Thanks for that, very informative. I am formulating a few questions on your comments, will post later. Need to beat the rain to mow lawn, and prepare basement for delivery of a gun safe.

    Russellc
     
    Last edited: Sep 16, 2017
  19. RussellC

    RussellC Member

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    My interest may fall into the "not much difference" category. What has me wanting such a device is to possibly sort out cases that will never make accurate ammo, (and much more importantly to me) check if a case was fine concentricity wise BEFORE I reloaded it, but not AFTER I reloaded it.

    I would like to think perhaps I could then correct what I was doing or not doing that caused the problem. While this may STILL fall in the not much difference category, it will be in the obsessive compulsive sleep better category! ( lawn still damp so cant mow yet...)

    Russellc
     
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  20. RussellC

    RussellC Member

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    Thats what I call in the "better sleep" category...I know exactly what you mean.

    Russellc
     
  21. 444

    444 Member

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    The thing for me is that I really enjoy reloading and playing around with these things. I realize that a lot of the stuff I think about and worry about are probably gilding the lilly. But, to me, spending time screwing around with reloading is less time I am rotting my brain in front of the TV. I would much rather be at my loading bench chasing the goal of producing perfect ammo than I would sitting in front of the TV watching something I am not really interested in along with an infinite string of commercials for stuff I have no interest in. Even if I can't shoot well enough to know the difference. If nothing else, it is interesting to me. And it gives me self confidence: when I am shooting, I know my gear (ammo, rifle......) is capable of a certain degree of accuracy and I know if I miss a shot it is on me.
     
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  22. GW Staar

    GW Staar Member

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    444! You sir, have the right idea, the right attitude, and the right mind set. Shooting, as well as reloading is a needed vacation from the world. And finding a niche in it that you can enjoy is the goal. That niche is different for each of us. Yet whatever niche it is, it might just prepare us for worse times.......and that is just gravy on top.:thumbup:
     
  23. marine one

    marine one Member

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    How do you correct a cartridge after you find it's out by .004 or .005 ?
    Do I pull bullet and start all over and re seat ?
     
  24. jgh4445

    jgh4445 Member

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    I went down this road as well. I ended up buying the Hornady. It works for me. I did take 5 or 6 boxes of "Match/Premium" ammo, by various manufacturers in my caliber, and measured them. Every one of them varied between .005 and.010. I was surprised that the so called "Good stuff" had such high numbers, but not surprised that my hand loads will usually out perform them accuracy wise.
     
  25. jgh4445

    jgh4445 Member

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    marine 1, the Hornady one has a knob that turns which pushes a post up against the bullet ( at about the ogive position) and you increase pressure on the bullet until your gauge shows the reading you want.
     

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